1. Field of Invention
The present invention is related to the field of devices for electronic testing and tracing of electrical circuits. More particularly, it relates to a device for identifying and testing the continuity of electrical wires, cables and cable networks.
2. Description of Related Art
Wire connectivity is essential to the proper function of telephone systems; cable television (CATV) systems; security systems; closed-circuit television (CCTV) systems; local and wide area computer networks (LANs and WANs); and, other multi-node, and multi-user systems. When a wire fault is encountered, the tracing of individual cables through wire bundles, and confirming their electrical continuity, often can be tedious and cause significant problems. Cables or wire are often not identified with corresponding tags, labels or color-coding at both ends, so technicians installing or testing pre-wired systems, or removing, repairing or re-routing the cables of an existing system, have to sort through and test each cable individually. This commonly entails sorting through a number of upstream wire ends at a junction box or panel, and testing each against individual downstream terminals where they connect to devices.
In the tracing of wires, in particular telephone and LAN type wires from its downstream terminus back to the junction box, a technician normally secures a short circuit or low-resistance wire terminator to the downstream terminus of the desired cable and then, back at the junction box, connects a volt-ohm meter (VOM) to each upstream wire end, one-by-one. All wires but the correct one will produce a substantially infinite resistance reading, while the desired cable will show continuity. If a standard 75-ohm terminator is used at the downstream terminal, a 75-ohm resistance reading on the meter confirms that no mid-wire short is present. Proceeding one-by-one through a great number of wire ends is a very tedious, laborious process. And, it is even more difficult and time-consuming if the technician desires to determine which of a multitude of downstream wire ends are associated with a particular upstream wire end at the junction box. In that case, the technician must either affix a terminator to the upstream end and walk room-to-room or workstation-to-workstation connecting a VOM to each downstream terminal, searching for continuity. Or, the technician must connect the VOM to the upstream end of the desired wire at the junction box and, repeatedly, walk to a downstream terminal; connect a terminator; and, walk back to the junction box to read the meter.
To aid technicians in trouble-shooting electrical wires and cables, various conventional devices have been used and proposed for more convenient testing and tracing of wire systems. Miniaturized, limited-purpose versions of VOMs having cables, probes, clips, adaptors, LED's, tone generators and streamlined cases are commonly available, but they are generally difficult to use among tangled masses of cable ends, and must be carried in a toolbox rather than in the technician's pocket. Accordingly, there is a need for an easily manipulable, easy to read device for testing and tracing of wire bundles. One such conventional device to perform the above mentioned type testing for coaxial cables is the Gale Cable continuity tester and tracer (Pocket Toner) of U.S. Pat. No. 6,437,580, which is incorporated herein by reference in its entirety.
Additionally, another deficiency with conventional continuity testers is that conventional continuity testers do not include a surge protector to protect the conventional continuity testers against over-voltage.
Accordingly, it appears there exists a need to adapt an easily manipulable, easy to read pocket continuity testing device for the testing and tracing continuity in multiple type of electrical circuits.